Flux doubling in continuous magnetic structures



SePt- 5, 1967 E. K. VAN DE RII-:T 3,340,517

FLUX DOUBLING IN CONTINUOUS MAGNETIC STRUCTURES Filed Feb. 1'7, 1964 3 sheets-shew 1 v Ln\ n a 1.-. n j LLI o@ Sept. 5, 1967 E. K. VAN DE RIE-:T 3,340,57

FLUX DOUBLING' IN CONTINUOUS MAGNETIC STRUCTURES Filed Feb. 17, 1964 3 Sheets-Sheet CONDUcTm@ ,/Loop h /NVENTOR A WOR/VE Y Sept 5, 1957 E. K. VAN DE RlET 3,340,517

FLUX DOUBLING IN CONTINUOUS MAGNETIC STRUCTURES 3 sheets-Snam :5

Filed Feb. 17, 1964 musom nul. .w04 ID MOH 30mm A 77'O/PNEY United States vPatent Oli ice 3,340,517 Patented Sept. 5, 1967 3,340,517 FLUX DOUBLING 1N CONTINUOUS MAGNETIC STRUCTURES Edwin K. Van de Riet, Palo Alto, Calif., assignor to Stanford Research Institute, Palo Alto, Calif., a corporation of California Filed Feb. 17, 1964, Ser. No. 345,312 6 Claims. (Cl. 340-174) Shift registers made of discrete magnetic cores and wire windings are known and used in data handling equipment. Because of the presence of wire coupling loops between cores, the rise time of pulses used for driving the register must be extremely short or coupling loop losses will drain away fluid so that by the time a driving pulse exceeds a required driving threshold there is insuicient flux -left to be transferred t-o the receiver core.

An object of this invention is to provide a unique shift register construction wherein the coupling loop loss of linx is eliminated.

Yet another object of the present invention is the provision of a novel and unique structure for la magnetic shift register.

Still another object of the present invention is the provision of a solid magnetic shift register structure which eliminates coupling loop wires and separate cores.

These and other objects of the present invention are achieved in a structure consisting -of a solid repeating structure made of substantially square loop ferrite material. This structure has a generally ladder-like structure. In the space between the rungs of the ladder, there are diagonals. The sides of the ladder in the space between the rungs of the ladder have the same length -as the diagonals in that space. The iterative structure may have an arbitrary length or may be closed upon itself in the form of a ring. A Efour-phase dri-ve source is necessary to operate the structure. Four drive windings extend from the respective four separate phase drives and couple to alternate rungs of the ladder structure for the purpose of driving same.

The novel features that are considered characteristic of this invention are set forth with particularity in the `appended claims. The invention itself both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawings, in which:

FIGURE 1 is a drawing of an embodiment of the in- 'vention illustrating magnetic uX pattern-s for storing a binary one yand for. storing a binary zero.V

FIGURE 2 is a drawing of an embodiment of the invention with a first and second phase winding, illustrating also magnetic flux .patterns which occur in the structure in response to the operation of a first phase windmg.

FIGURE 3 illustrates the magnetic flux patterns which occur in the structure of FIGURE 2 in response to yactuation of the second phase winding.

FIGURE 4 is a drawing of an embodiment of the invention with a third and fourth phase winding, illustrating also magnetic ux patterns which occur in response to eX- citation of the third phase winding.

FIGURE 5 is a drawing of magnetic ux patterns which occur in the structure of FIGURE 3 in response to the excitation of the fourth phase winding.

FIGURE 6 is a drawing showing an alternative arrangement for the crossover structure which may be used in the embodiment of the invention.

FIGURE 1 illustrates the structure of this invention without the required four phase drive windings and input and output windings, for the purpose of preserving clarity and for illustrating the structure of the solid magnetic register. The structure shown in FIGURE 1 may be made up of substantially square hysteresis loop magnetic material. By way of illustration, and not by way of limitation, a four section structure is shown with a beginning and an end. Since the structure shown compensates for ilux losses, it can be made as long as desired and may be closed upon itself to establish a ring structure. As is the case with the usual discrete element shift register structure, the respective sections 11, 12, 13, 14 will be designated as odd and even shift register stages or sections.

The structure has a ladder-like 20, 22, 24, 26, 28 of the ladder are separated by the sections 11, 12, 13, 14. Preferably, the cross-sectional area of each rung of the ladder is twice that of the respective structure comprising the sections. Each section includes two diagonals respectively 11A, 11B; 12A, 12B; 13A,

13B; and 14A, 14B. Each section further includes two side pieces respectively 11C, 11D; 12C, 12D; 13C, 13D; 14C, 14D. The length of each side piece substantially equals the length of each diagonal. 'Ihese lengths should be greater than the length of the rungs. The greater these lengths are, the more eicient the register. However, this also increases the size and cost of the register. For the purpose of simplicity, it is assumed that there is one unit of flux which can till the side pieces and diagonals, and two units of flux whic-h can till rung structures. In connection with the structure shown, it is also assumed that the diagonals do not touch each other where they cross.

The flux directions represented by the arrows in sections 12, 13 and 14 are assumed to be indicative of the flux directions when these sections are in their clear or zero representative states. The direction of ux represented by the arrows in section 11 is indicative of the flux direction when section 11 is in its one representative state. It will be seen that when a section is in its clear state, then the flux in the side piece portion of a section, for example 12C and 12D, appears to circulate in a clockwise direction. The ux representative arrows in the diagonals 12A and 12B point toward side piece 12C. When a section, such as 11, is in its one representative state, then the flux in the side piece portions 11C and 11D appear to circulate in a counterclockwise direction, and the flux arrows in the diagonals point toward the lower side piece 11D.

The application, in proper sequence, of magnetomotive forces to the shift register structure shown in FIG- URE 1, can transfer the one representative state of a section along the structure in the same manner as occurs with the usual shift register made up of discrete magnetic cores. Consider now FIGURE 2, which is the same structure as is shown in FIGURE 1 with the addition of two .phase windings including a first phase drive winding 30 connected to be driven from a phase 1 drive source 32, and a second phase drive winding 34 connected to be driven from a phase 2 drive source 36. An input winding 52 is driven from an input data source 50. The input winding is wound around rung 20 passing through the space between this rung and the diagonals 11A and 11B. Output from the register is detected by a winding 56. This winding is coupled to rung 28 and is connected to an output device 54.

The phase 1 drive winding 30 is iirst Wound around the junction of structures 11B and 11D passing through the space in section 11 which is between two diagonals and the rung 22. It is next wound around the junction of structures 12A and 12D passing through the space defined by the two diagonals 12A and 12B and the rung 22. It thereafter similarly and redundantly extends to and through the space defined by the two diagonals 13A and 13B and the rung 26 being wound on the junction of 13B and 13D, then passes around the rung 28 to be wound configuration. The rungs I around .the junction of 14A and 14D and to extend through the space defined by the diagonals 14A, 14B and the other side of the rung 26. The phase 2 drive winding 34 extends from the drive source 36 through the-opening provided between the two diagonals 11A, 11B and the rung 22 bein-g wound on the junction of 11B and 11D. It then extends through the opening provided by the diagonals 12A, 12B and rung 24 being wound on the junction of 12B and 12D. It then extends redundantly through the opening provided by the diagonals 13A, 13B and the rung 2'6, being wound on the junction of 13B and 13D, finally extending through the opening provided by the diagonals 14A, 14B and rung 28 being wound on the junction of 14B and 14D.

For the purpose of illustration, let it be assumed that the iirst section 11 is in its one representative state as shown in FIGURE 1, and the remaining sections are in their zero representative states. FIGURE 2 shows the flux directions in the register after a phase 1 drive. During clock phase 1, the drive winding 30 receives a current pulse. The applied magnetomotive forces cause ux to reverse direction in a closed path including the magnetic structures 22, 12C, 24 and 12D. The sense of the winding 30 and number of turns used is such as to prevent switching in any path which includes the diagonal structures for the zero case. In other words, the diagonals 12A and 12B are maintained with their ux in the clear directions while the flux directions in the side structures 12C and 12D are switched. The flux directions in section 11 are still not affected by the phase l drive.

FIGURE 3 illustrates, with arrows beneath associated structure, the liuX pattern resulting in the register, shown in FIGURE 2, after a phase 2 drive. A current pulse applied to the winding 34 from the phase 2 drive source has the affect of causing the flux to switch around to the clear state directions in section 11 and to complete the one state ux directions in section 12. The sense and number of turns of winding 34 on the structure also is such as to prevent switching in any paths which includes the outer side structures. Furthermore, the sense of the coupling of the winding 34 is in such a direction as to hold the rung structure 22 in its clear state. The switching operation which occurs in rung 24 brings this run-g the rest of the way to saturation.

After excitation of the phase 2 windings, as may be seen in FIGURE 3, the flux in diagonals 11A, 11B, side pieces 11C and 11D and rung section 22 have been driven so that they are in their cleared states, diagonals 12A, 12B, side pieces 12C and 12D' and rung 24 have been driven so that they are in the one state. Thus a one is transferred from section 11 structures to section 12 at the end of two clock phase drives.

The transfer from section 12 to section 13 is accomplished in similar manner by the successive application of current pulses to the phase 3 and phase 4 drive windings, respectively 38 and 42, as shown in FIGURE 4. These windings are respectively driven from phase 3 and phase 4 drive sources respectively, 40 and 44. It may b e seen in FIGURE 4 that the respective phase 3 and phase 4 windings are coupled to the structures constituting sections 12 and 13, respectively, in the same ymanner as the phase 1 and phase 2 drive windings are coupled to the structures constituting sections 11 and 12.

The arrows shown in FIGURE 4 represents the direction of the ux after a phase 3 drive has occurred from the phase 3 drive source 40. It will be seen that the flux direction of the side pieces of section 13 has been reversed and there has been a partial reversal of flux in rung 26.

After the phase 4 drive source 44 has applied a current pulse to the phase 4 drive `winding 42, the resulting magnetic flux pattern is represented by the arrows shown in FIGURE 5. The transfer of a one from the section 12 to section 13 position is now completed and section 12 is left in its lclear state.

A preferred tur'ns ratio for the drive windings on the shift register structures is, for drive winding 30, one turn around structures 11B and 11D, three turns around structures 12A and 12D, and then this is repeated adjacent every subsequent alternate rung. For drive Iwinding 34, five turns around structures 11B and 11D, one turn around structures 12B and 12D,'and thereafter this pattern is repeated for the following portions of the register structure to which winding 34 is coupled. Drive winding 38 winds around structures to the left of the rungs with one turn and winds around structures to the right of the rungs with three turns, in similar fashion to drive ewinding 30. Drive winding 42 winds around structures in the even sections with i-ve turns and around structures in the odd sections with one turn, analogous to winding' 34 on the respective odd and even sections.

The structures described is similar to discrete magnetic core and wire shift registers in that it requires two sections of structures for one lbinary bit of information, since during one-half cycle (two clock phases), the information is transferred from eac-h even numbered section to its adjacent following odd numbered section. During the other half cycle, the information is transferred from each odd numbered section to its adjacent following even numbered section. In the case of the open structure shift registers, as shown in FIGURE 2, data may be introduced into the shift register by means of an input data source 5i) which applies a pulse of current to an input winding 52, which is coupled around the rung 20. Data output is sensed lby means of the output device 54 to which an output winding 56 is coupled. The output Winding is inductively coupled to the rung 28 and whenever there is a reversal of the ux in the rung 28, a voltage is induced in this output winding which is sensed by the output device.

The basic reason :for the need for gain is the same in the shift register described herein as it is in all others. Since the structures shown herein lhave no wire coupling loops in which turn ratios can be incorporated, gain is obtained by using a ux doubling technique. The binary one representative state does not build up indefinitely here because of iiux saturation of the lbranch structures.

It `was previously stated that the side structures and diagonals have half as much ux capacity as the rungs. Thus, the flux capacity of the rung structures may be designated as two units and the flux capacity of the diagonal and side structures ymay be designated as one unit each. Now assume, for example, that due to air flux losses, the ux in the structures of section 11, constituting the flux in side sections 11C and 11D and in the diagonal sections 11A and 11B, are each three-quarters of a unit. Then rung 22 will only have one and one-half the units of ux or will only be three-quarters saturated. When, during clock phase 1, flux is switched around the path made up of rung 22, side sections 12C and 12D, and rung 24, side section 12C and 12D reach saturation before rung 22 is cleared. The switching stops when -rung 24 saturates so that rung 22 is left with half a unit of ux still not cleared. During the second clock phase, Vthe structures of section 11 switch a total of one and one-half units; one unit is switched through diagonals 12A and 12B and one-half unit is switched through rung 22, thus completing the clearing of rung 22. Note that when saturation of the diagonals and of the side sections are referred to, it means that they are saturated at the junctions with the rung and it is assumed that due to air ux loss, they are only three-quarters saturated at their junctions Vwith the succeeding rung.

The same line of reasoning as given above can be used to show that a 1 level of flux `will propagate if the air flux and elastic losses (and possibly some other complicated losses due to imperfect` geometry) are 50% or less. The zero level of flux can be prevented from building up by driving rung 24 in the clear direction `during -cloc-k` are -well known and may be applied here to keep the zero level from building up.

The magnetic structure of the shift register may lbe formed into a register having a beginning and an ending as shown in the drawing, or may be formed into a circular or endless register. In this event, in order to avoid any problems which can arise due to closed flux paths around top side sections and around bottom side sections of the circular register structure, the drive windings may 'be wound on the register so that one half the driving ux is applied at the lower junctions formed by each diagonal lower side section and lower end of a rung, which is shown in the drawings, and the other half of the driving flux is applied at the upper junctions, each of which is formed by each diagonal, upper side section and upper end of a rung. This may be accomplished by having the drive windings of one half of an endless register wound around the lower junctions and the drive windings for the other half of the register wound around the upper junctions. Alternatively, the drive windings may be rWound about both upper and lower junctions throughout the endless register and either one half the required drive current be applied to the windings, or one half the number of turns used, whichever is desired to achieve the required number of driving ampere-turns.

From a practical structural fabrication point of view, the crossing of the two parts of the diagonals may be inconvenient. To avoid this problem, a crossover may be made in the form shown in FIGURE 6 comprising an actual junction 64 of diagonals 60, 62, with a steering loop 66. The loop is conductive and effectively steers the ux across the junction without letting it turn. Any attempt by Ithe ux to turn, results in a current induced in the conducting loop which in turn provides a magnetic motive force which opposes the turning ux. As a result, the diagonals shown in the structure embodying this invention may meet at their cross over point when a conducting loop such as shown in FIGURE 6, is used.

For simplification of the drawing the windings required for obtaining a negation function register are shown partly in FIGURE 7 and partly in FIGURE 8. FIGURE 7 and FIGURE 8 show the identical magnetic structure as was shown previously except that the sense of the coupling of the respective phase l, phase 2, phase 3 and phase 4 drive windings, respectively 70, 72, 74 and 76, respectively driven from phase l, phase 2, phase 3 and phase 4 drive sources, respectively 78, 80, 82 and 84 are such as to perform a negation function. That is, the register functions to transfer data stored as a binary one as a binary zero and data stored as a binary zero as a binary one. Thus, if a binary zero is stored in all sections after excitation of drive windings 70 and 72 by the respective phase l and phase 2 drive sources, a binary one will be stored in sections 12 and 14 and a binary zero will be stored in sections 11 and 13. After excitation of drive windings 74 and 76 by the respective phase 3 and phase 4 drive sources then a binary zero is stored in all sections again. If sections 11 and 13 initially stored a one and the remaining sections stored a zero, then after the first two phase drives the entire register would be storing zeroes. After the third and fourth phase drive sections 12 and 14 would be storing ones and sections 11 and 13 would be storing zeroes.

In FIGURE 7, the phase 1 windings 70 winds around the junction of diagonal 11B, side piece 11D and rung 22, -then passing around the junction of diagonal 12A, side piece 12D and rung 22. A preferred turns ratio here is l to 3 as it was for the phase l winding shown in FIGURE 2. The phase l drive winding 70 winds on the junctions similarly positions adjacent alternate rungs of theA structure.

The phase 2 winding 72, besides winding around the same junctions as the phase l winding, with an opposite sense however, also Winds around one junction of each succeeding rung. This junction is the one on the side of the rung adjacent a preceding rung about which both rst and second phase windings pass. Again, it is noteworthy that this winding is wound about the same junctions as the phase 2 winding in FIGURE 3 and with the same relative sense. The turns ratio preferred is, in left to right order, 7 to 2 to 1.

In FIGURE 8 the phase 3 drive winding 74 winds about the same junctions as does the phase 3 winding in FIGURE 4. Effectively this winding 74 is the same as winding 70 except that it is displaced by one junction. Similarly the phase 4 winding 76 is the same as the phase 2 winding 72 except that it is displaced by one junction.

The improvement offered by continuous structure ux doubling arrangement shown and described herein over the shift register structure made of discrete elements coupled with conducting wire is that, in eliminating the wire loop, the main transfer los is eliminated, making possible greater power requirements. Als-o the requirements on drive pulse shape are greatly relaxed. This structure lends itself to miniaturization since the problem of reducing aperture size while maintaining a required number of turns for the smaller sizes in multiaperture core shift registers, is eliminated. It is possible to use the structure described herein in logic-memory or logic-output interfaces. Thus, for example, there is a possibility of going from a small to a large signal by ux amplification from one end of the structure to the other. Output may be taken from any section of the present invention by a coupling loop wound on a side piece or a diagonal.

The coupling of the drive windings on the junctions -of a diagonal side section, and rung shown as -being located at the bottom Vof the respective sections may if desired be located at the top of the respective sections, since the structure is symmetrical. They can also be alternated. Also, while the embodiment of the invention is shown as planar, it is still within the spirit and scope of this invention to bend or twist the structure shown so that it is not planar.

There has been described and shown herein a novel, useful, and unique structure for a magnetic material shift register.

I claim:

1. A magnetic shift register structure comprising a structure made of magnetic material having a substantially rectangular hysteresis characteristic, said structure being substantially in the shape of a ladder, said ladder having rungs joined by side sections, diagonals extending between the rungs of said ladder structure, the length of each side section being substantially equal to the length of a diagonal, the cross sectional area of said side sections and diagonals being substantially identical and being less than the cross sectional area of a rung, and winding means coupled to said tructure for determining the transfer of data therein.

2. A magnetic shift register structure comprising a structure made of magnetic material having two states of magnetic remanence, said structure having a substantially ladder like appearance with the rungs of said ladder being spaced from each other by side sections, diagonals extending between the rungs of said ladder, the length of each side section equalling the length of a diagonal, said side sections being bent to enable them to iit between rungs, the cross sectional areas of each side sections substantially equalling the cross sectional areas of each sidediagonals, said diagonals and side section cross sectional area being substantially one half of the cross sectional area of the rung, and Winding means indu'ctively coupled to said structure for altering the flux state of successive diagonals, and sections and rungs for representing the transfer of data through said structure.

3. A structure as recited in claim 2, wherein said winding means comprises a first winding which at every alternate rung is first wound around the junction of a diagonal and side section on one side of said rung and then is wound around the junction of a diagonal and side section on the other side of said rung, a second winding which at one side of each succeeding rung is wound around the junction of a diagonal and said section with said rung, a third winding which for those of said rungs other than said alternate rungs is rst Wound around the junction of a diagonal and side section on one side of said rung and then is wound around the junction of a diagonal and side section on the other side of said rung, and a fourth winding which at the other side of each succeeding rung is wound around the junction of a diagonal and said section with rung.

4. A structure as recited in claim 2 wherein said diagonals are spaced from each other at their crossover location.

5. A structure as recited in claim 2 wherein said diagonals intersect with one another at their crossover location, and a closed conducting loop encircles ,said crossover location.

6. A magnetic shift register structure comprising a plurality of iterative sections, each section comprising magnetic material having a substantially rectangular hysteresis characteristic, each section comprising a six sided gure with two opposite sides parallel to each other and larger than any of the other sides, diagonals extending between said two opposite sides, each of the remaining sides being one half of the length of each diagonal, the cross sectional area of said opposite sides exceeding the cross sectional area of said diagonals and said remaining sides,

and winding means coupled to said sections for altering the ux states of said sections.

No references cited.

BERNARD KONICK, Primm Vrxfmw'ne.

P. SPERBER, Assistant Examiner. 

